Mud flow indicator and system therefor



May 23, 1961 B. E. TAYLOR 2,985,731

MUD FLOW INDICATOR, AND SYSTEM THEREF'OR Filed March 3, 1958 a l /f i/754 MIXING RETURN 2 v PUMP PIT PIT sHALE lg /f Fly! ALARM United StatesPatent M' FLow INDICATOR AND SYSTEM THEREroR Ben E. Taylor, P.0. Box 92,Weatherford, Tex.

Filed Mar. s, 195s, ser. No. 118,623

z claims. (ci. zoo-31.9)

My invention relates to indicator devices and systems, and moreparticularly to devices and systems for giving indications of drillingmud flow conditions in an oil well drilling operation. This applicationis a continuation-inpart of my co-pending application S.N. 658,841, ledMay 3, 1957, now abandoned.

In an oil well drilling operation, a special composition known in theindustry as drilling mud, is circulated in the drilled hole. Thedrilling mud is pumped down the hole via the drilling pipe, and isforced back up the hole in the space between the drilling pipe and thehole bore or casing pipe. The mud serves to enhance the cutting actionof the drill bit, seal the hole walls, carry the cuttings up out of thehole, and also to keep formation pressures under control. The quantityof mud required for the circulating system of a drilling operation isobviously quite large, and the money value of this quantity of mud issubstantial, amounting to many hundreds of dollars. When drilling inlocations where porous formations are encountered, it often happens thatthe drill breaks into a porous strata and a large quantity of mud ispumped out into the cavities of the formation and irretrievably lostbefore the driller realizes what has occurred. Loss of mud circulationcan also occur as a result of clogging in the drill bit nozzles oropenings. When this happens, the cutting eiciency of the bit is greatlyreduced. If there were some way to appraise the driller immediately whenmud circulation is being lost, much waste could be prevented. It hasbeen reliably estimated that several thousand dollars per well could besaved in some locations, by electively minimizing mud waste. The problemof mud waste has been approached a number of ways in the prior art ofwhich I am aware, but no eifective solution has yet been found.

Another problem encountered in oil well drilling operations is that ofblow-outs. A blow-out is a condition resulting from excessive gaspressure acting to force the drilling mud back up out of the hole. Sincea blowou can cause serious difficulty, it is common practice to providedevices known as blow-out preventers, which are valve or plug typedevices which when closed, act to seal the top of the hole. In mostcases it is necessary to pull up the kelly before the blow-out preventercan be closed. The problem has been that of providing suicient advancewarning of imminent blow-out to enable the drilling crew to carry outthe steps necessary for closing thevblow-out preventer.

It is accordingly a general object of my invention to devise effectivemeans for minimizing drilling mud waste.

More specifically, it is an object of my invention to devise anarrangement and system wherein an alarm will be actuated immediatelyupon loss of mud.

Another object of my invention is to provide a simple and elective mudflow sensing and alarm actuating device.

Another object of my invention is to provide an economical and eiectvemud flow sensing and alarm actuat- Patented May 23, 1961 ing devicewhich can be readily installed in the return line of mud circulatingsystems.

Another object of my invention is to provide a simple and effectiveblow-out sensing and alarm actuating device.

Another object of my invention is to devise an arrangement and systemwherein an alarm will be actuated immediately upon excessive drill 4bitclogging or plugging- Another object of my invention is to devise anarrangement and system wherein an alarm will be actuated immediately toindicate abnormal mud circulating conditions.

These and other objects are effected by my invention as will be apparentfrom the following description taken in accordance with the accompanyingdrawing, forming a part of this application, in which:

Fig. 1 is a block diagram showing a typical mud circulating systemembodying my invention;

Fig. 2 is a schematic perspective View showing a sensing and alarmactuating device in accordance with a preferred embodiment of myinvention;

Fig. 3 is a schematic side elevational view partly in section of thedevice of Fig. 2 in its alarm actuating positions; and

Fig. 4 is a schematic block diagram illustrating the electrical circuitof the alarm system.

In the mud circulating system shown in Fig. l, mud is taken from themixing pit 11 to the pump 13 which pumps it down the drilling pipe l15.The mud then goes down to the drill bit (not shown) and is forced backup in the space between the drilling pipe 15 and the hole bore casing17, from whence it is piped to the shale shaker 19, and from the shaleshaker to the return pit 21, and from the return pit back to the mixingpit 11. The indicator actuator device of my invention is inserted in themud return 'line just ahead of the shale shaker 19.

A section of the return line 23 at the indicator actuator location isshown in Fig. 2. The return line is prepared for installation of theindicator actuator device by welding onto the top of the return line areceptacle 25 which is a short section of pipe, one end of which isshaped to conform to the outer surface of the return line pipe 23. Thereturn line pipe is also provided with a slot 27 extending along adiameter of the receptacle 25 and longitudinally of the return pipe 23.The indicator actuator device comprises a body portion 29, a pendulumpaddle 3.1, a pendulum arm 33, a support shaft 35, and a pair of mercury(Hg) switches 37, 39. The body portion 29 has the shape of a shortcylinder having an outside diameter which is just less than the insidediameter of the receptacle 25, so that the body will nest into thereceptacle. The upper end portion of the body exterior is of increaseddiameter to form a shoulder 41, and carries threads 43. The body isprovided with a pair of bearing slots 45, 47 located at the upperportion of the body 29, one at each end of a body diameter. Each slot45, 47 is open at the top, extends downward to a point just above thelower extent of the threads 43, and has a semicircular bottom. The lowerportion of the body 29 carries four pins 49 90 degrees apart at a commonlevel near the body lower end. The pins 49 project a short distanceoutwardly from the body 29. The receptacle 25 is provided with fourcrankshaped slots 51 located 90 degrees apart and opening to the upperend of the receptacle 25. The pins 49 on the body portion are adaptedfor co-op eration rwith the crank-shaped slots 51.

The pendulum paddle 31 is a relatively heavy piece of metal platematerial shaped to conform generally with the inner surface of thereturn line 23, with enough clearance to allow for adequate swingingmovement. The

pendulum arm 33 is a metal rod which is tixed at one ing or brazing. Thesupport shaft 35 isma,cylin dricalY metal rod. The shaft has a centralportion 53 which spans a diameter of the body portion aforementioned,addr end portionsof reducedl diameter justless'than the width of thebody bearingslots. Oneshaft endiportion 5-5..terminates at the bodyexterior-surface, while the other shaft end portion 5'7v extendsoutwardly' beyond the body exterior to serve as a mount for the; mercury,switches` 3.7, 39, as will be hereinafter morefully explained. The freeend of the pendu-luml arm,` 33 is fixed to the center of the shaftcentral portion 53 by suitable means, eg., by welding or brazing.,vThus, thependulum paddle 31` acts as a variabley obst-ructionfinthereturnline 23, and the pendulum armA 3-3k canl swing on thesupport shaft3S in a vertical plane bisecting the return pipe. The pendulum arm-33 iscurved so that the paddle.v obstruction of the returnline 23,'is maximumat onefextreme. position ofthe arm andl minimum at the other. extremeposition of the arm. The bulbs ofthemercury switches37, 39 are containedin respectiveA weatherproof housingsv 59, each having contacts which arebrought out, to a pair of'rterminals 61 at the housing exterior. Thehousings 59 are each provided with a bore of proper size toA fitthe.shaft end portion 57. The housings 59are also. each. provided with a`threaded bore adapted for receiving a: shaftg lock screw` 63. Thus, thehousings 59rmay be fixed in. any radial position on the shaft endportion 57. The indi.- cator' actuator device may be closedv at itsupper end by means of a cap 65 which is adapted for threading onto thetop of the body 29. To install theindicator actuator device, the paddleof the indicator actuator is passed down through the return line slot27- and then theindicator actuator is rotated so that thepins 49 areover the slots 51, and then it is lowered and-rotated: to` seatingposition. The paddle is of4 course oriented properly with respect to.the mud flow direction. mud` flow-direction is from leftv toright. Theelectric alarm circuit for the indicator actuator system is shown byFig. 4. One terminal of. each mercuryv switchy 37, 39 isconnectedthrough. a.battery.64 to ground at 66. The otherterminal of each mercuryswitch 37, 39 is con nected in series withA a respectivesingle poleswitch 67, 73:- and arespective alarm device 69, 75 to a ground at 71-Thealarm devices 69,I 75 may be of any suitable electrically energizednoisemaker type, such as buzzers, bells,f or horns., Thealarm devices69,75 and single pole switches 67, 73- are preferably installed atalocationconvenienttofthe drilling rig operator. The-purpose of the single` poleswitches is to provide for manual energization;andrdefenergization. ofthe respectivealarm circuit.

As; hereinbefore stated,.the .device of my invention performs-threeimportant functions, namely, itprovides adequate warning in cases` ofmudfloss, drill bit plugging, andv incipient blow-out conditions. Inoperation, with mud flowing normally in the return line, the paddle 31floats on top of the mud Vstream in:anintermediate positionwhichwis.approximately that shown in Fig. 2. Under theseconditions, the housingof the `rstmercury switch 37 is; adjusted, on the shaft end portion 57to a-position such that itscontacts are open, and then islocked-inpositionffbymeans of the lock'screw 63. The housing ofthefirst-mercury switch 37 is placed on the shaft endportion' 5-7 in the,position such thatits contacts will be closed by clockwise movement ofthe shaft: 35. The second mercury-switch 39.is also adjusted'onthefshaft endrportionV 5J to aposition such that its contacts areopenduring'the normal; mud flowcondition, but ittis placed onA the shaftendg; portion 57 inthe position such'A that its contacts will be closedby counter clockwise movement of the Vshaft 35.-.r Nowtif atporousstrata isrencountered'inthe-'hole being drilled, so that-mud willflowinto the strata instead ofbeingforcedback up and outof the hole,l orif 'there is- In- Figs. 2 and 3, the

ases/ra 1v thek maximumV obstruction position (for example, as shown bythe solid lines in ,Fig 3). The rst mercury switch 37 is at the sametime rotated, or tilted, to cause its contacts to close to energize itsalarm circuit, while the contacts of the second mercury swit-ch 39remain open. Now if a region of excessive gas pressure is encountered inthe hole presaginga potential blow-out, it will have the effect ofapplying additional pressure on the returning mud, thus. causing themudflow levelV in the return pipe 23 to increase, whichy in. tur-n causesthe paddle 31 to ride at a higher level, which rotates the shaft 35counter clockwise, tilting the second mercury switch 39 to the closed,contacts position (for example, the position shownv by dotted 'lines inFig. 3), while at the same time the contacts of the first mercury switch37 remain open. The alarm circuit of the second mercury switch 39 isthus energized. When either alarm circuit is energized, of coursethegrespective-alarm. device'will be actuated alertingthe drillingmigoperator, .who can= then immediately take` the necessary precautionaryac,- tions and` effect appropriatecorrective measures..

It is understood that the amountA of paddle swingI required to cause thecontacts of a,respective.v mercury switch` to close can bepredetermined, andthe sensitivity ofrespective switch. actuationcanbe.selected.as desired.

The indicator actuator device, and system disclosed herein has proved tobe very effective inactualoperation. It is es timatedythat inv manycases `asmuch asr several thousand dollarsl per wellcould-l be savedbyl-utilizingf the device and system. of. my inventionto minimizedrilling mud losses. Also, my,l inventiony may be utilized-toren'-vhance drilling efficiency, since it `provides indicationof bit plugging.Furthermore, my inventionimaybe utilized to minimize the possibility ofdanger and heavy lossesbody cap 65, because no significant amount ofmudf passes up through the return. line slot 27. While the.

shaft constructionV which Ifhavefshown isaA convenient` form, obviously.theV shafty could bey constructed-inv other forms. Also, the Vshape ofthe pendulum paddle could. take any form which would providesufiicientiobstruction and. have sucient weightv to operate properly.

While I have shownmy invention in only one form; it will be obvious tothose skilled'inthe art thatf it is` not; so limited, but is susceptibletovvarious changes and modi-- iications without departing from thespirit thereof.

I claim:

l. A mud ow indicator actuator for anoil Well drilling layoutcomprisingan element suspended from a support located above a mud returnlineand adapted for free swinging motiony in aV vertical plane bisectingsaid return line, said. elementk beingr disposed'in'said.V return lineso as to oat on the mud flow streami andlmove re,

sponsive to variationsgin mud flowconditions,.iirstswitciil meansactuated responsive to. an increase in` mudy flow'.-

turn line; a receptacle shaped at one end to conform toY the uppersurface lof said return line andweldedthereto with its centralaxisperpendicular to the1-returnline cen-` tral axis; an indicator actuatorcomprising acylindrical body portion adapted for nesting-,insidesaidreceptacle,

a pendulum support shaft journaled for. free oscillatory movement onsaid body ata diameter thereof, arelatively heavy gravity responsiveflow. obstruction-paddle sus-v pcrtded from said shaft by means ofapendulum arm and:

so as to provide maximum obstruction insaid. return line at one extremepositionlof said arm, and minimum obstruction at the other extremeposition of said arm;.`

being'mounted so asto be actuated when said' shaft`s` 5 rotated in aclockwise direction from a normal position, said second switch beingmounted so as to be actuated when said shaft is rotated in acounter-clockwise direction from said normal position.

References Cited in the tile of this patent UNITED STATES PATENTS410,502 Donner Sept. 3, 1889 1,428,645 McDonnell Sept. 12, 19221,653,177 Herz Dec. 20, 1927 1,888,737 Richmond Nov. 22, 1932 f3 KinyonNov. 28, 1933 rIyden Oct. 3, 1944 Voliazzo et a1. June 10, 1947 Moore etal July 12, 1949 Havens July 4, 1950 Reynolds Sept. 23, 1958 FOREIGNPATENTS Germany Mar. 27, 1923 Germany Feb. 15, 1941 Germany Jan. 3, 1944

